Hydraulic aggregate

ABSTRACT

The present invention relates to a hydraulic aggregate for a slip-controlled brake system which includes noise damping chambers integrated in a pump bore, wherein there is a hydraulic connection between the brake pressure generator ports and the noise damping chambers by means of pressure fluid channels that open radially or tangentially into the pump bore and are connected to the valve accommodating bores of the first valve row of an accommodating member in which the inlet valves are received.

TECHNICAL FIELD

The present invention relates to a hydraulic aggregate for aslip-controlled brake system.

BACKGROUND OF THE INVENTION

A hydraulic aggregate of the above-mentioned type is disclosed in WO91/16220. It is disclosed in this publication to arrange the noisedamping chambers in parallel to the low pressure accumulator bores whichare, thus, jointly aligned in one row laterally of a pump bore. Thepressure fluid channels for the brake pressure generator ports at theblock-shaped accommodating member extend vertically through the valveaccommodating bores provided for the inlet valves and laterally pass bythe pump bore into the bottom area of the noise damping chambers.Extending in parallel to each pressure fluid channel that opens into thenoise damping chamber is another vertical pressure fluid channel foreach brake circuit which exclusively connects the pump bore to the noisedamping chamber.

The result is a block-type construction that exceeds the shape of ablock, i.e., has considerably differing edge lengths, in order to beable to realize the necessary noise damping chambers and the lowpressure accumulator bores. On the other hand, there is the need toremove a large machining volume from the block by means of variousdrilling operations from different directions. Consequently,sophisticated measures are needed, especially for making the noisedamping chambers and the necessary pressure fluid channels. Further, thechosen split-up of the valve rows necessitates locating the wheel brakeports on both lateral surfaces of the block-shaped accommodating memberso that a connection pattern for the pipe system is achieved which issplit onto three lateral surfaces of the accommodating member. This, inturn, requires more space and increases the number of assembly stepsneeded.

In view of the above, an object of the present invention is tomanufacture a hydraulic aggregate of the above-mentioned type which isdimensioned as small as possible and is as inexpensive as possible tomake. A special object is to reduce the effort in manufacture forconnecting the noise damping chambers to the brake pressure generatorports, and the hydraulic connections of the pump bores and the secondvalve row that accommodates the output valves along with the noisedamping chambers and the connection of the low pressure accumulatorbores by way of the pump bore to the noise damping chambers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a perspective view of the arrangement of bores in a housingby using pressure fluid channels that open exclusively vertically intothe square accommodating member of a hydraulic aggregate.

FIG. 1b is a cross-section taken through the accommodating memberaccording to FIG. 1a in the plane of the pump bore.

FIG. 2 is a perspective view of another embodiment of a hydraulicaggregate with pressure fluid channels that open both vertically andtransversely into the block-shaped accommodating member.

FIG. 3 is a perspective view of a block-shaped hydraulic aggregate witha connection pattern for the brake pressure generator ports and wheelbrake ports that is modified compared to FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1a shows a hydraulic aggregate for a slip-controlled brake system,including a block-shaped accommodating member 1 which accommodates inletand outlet valves in several valve accommodating bores 2 of a first anda second valve row X, Y and which includes a pump bore 3 outside the twovalve rows X, Y which points transversely to the direction in which thevalve accommodating bore 2 opens into the accommodating member 1.Further, a motor accommodating bore 4 which opens vertically betweenhalf the bore length into the pump bore 3 is arranged outside withrespect to the two valve rows X, Y. In addition, low pressureaccumulator bores 5 are arranged in the accommodating member 1 outsidethe two valve rows X, Y, the bores 5 pointing vertically to the axes ofsymmetry of the valve accommodating bores 2 and vertically to thelongitudinal axis of pump bore 3 into the accommodating member 1.Several pressure fluid channels 2′, 3′, 5′ which connect the valveaccommodating bores 2, pump bores, and low pressure accumulator bores 3,5 ensure a hydraulic connection between two brake pressure generatorports THZ provided in the accommodating member 1 and the four wheelbrake ports HR, HL, VR, VL. Further, two hollow-cylindrical noisedamping chambers 6 are provided in the pump bore 3 and connected to thebrake pressure generator ports THZ that open into the accommodatingmember 1, directly by way of the pressure fluid channels 3′ that extendtransversely to the pump axis. According to the present invention, thenoise damping chambers 6 are hence integrated in the pump bore 3, andthe brake pressure generator ports THZ are in connection to the noisedamping chambers 6 by way of pressure fluid channels 3′ that openradially, preferably tangentially, into the pump bore 3 downstream ofthe pump pressure valves. The pressure fluid channels 3′ each include abranch line to the valve accommodating bores 2 of the first valve row Xthat accommodates the inlet valves. The noise damping chambers 6 arearranged in the diametrically disposed ends of the pump bore 3 so that,advantageously, both the noise damping chambers 6 and the pump bore 3are pressure-fluid tightly closed by means of closure members 7 insertedfrom outwards into the two lateral surfaces of the accommodating member1. The pump bore 3 which penetrates the accommodating member 1 at rightangles relative to the low pressure accumulator bores 5 includes astepped portion 10 (see explicitly FIG. 1b in this respect) in the areabetween the bore portion that is provided for the two pump pistons andthe noise damping chamber 6, on both sides of the radial piston pump.Pump suction channels 5′ open into stepped portion 10 in the directionof the low pressure accumulator bores 5. The pump suction channels 5′are provided in a particularly space-saving fashion by the combinationof an accommodating bore for the pump suction valve (non-return valve)that is respectively fitted into the bottom of the low pressureaccumulator bore 5 and by a milling operation inside the pump bore 3.The latter operation is effected in each case by introducing a peripherymilling tool into the pump bore 3, which tool must remove only a smalllayer from the pump wall in the direction of the accommodating borearranged within each low pressure accumulator bore 5. This obviates theneed for deburring of the pump bore 3 which has previously beennecessary due to the drilling operation in this area, and also for asophisticated pump suction channel. Instead, the pump channel 5′ may berealized to become extremely short due to the accommodating bore for thepump suction valve meeting the milled slot of the pump bore 3 fromopposite directions. Also, the pump bore 3 has an axial offset on eitherside of the motor accommodating bore 4 in order to minimize the surfacewear in the pump bore 3 due to the pistons of a radial piston pumpmoving therein.

The second valve row Y comprises exclusively the valve accommodatingbores 2 provided for the outlet valves which are optimally disposedbetween the pump bore 3 and the first valve row X that exclusivelyincludes the valve accommodating bores 2 for the inlet valves. Theresult are especially short, straight pressure fluid channels 2′ betweenthe two valve rows X, Y and an extremely favorable connection betweenthe valve row Y and the low pressure accumulator bores 5 via the returnchannels 5′. The pump suction channel 5′ that is arranged between thepump bore 3 and the low pressure accumulator bore 5 is rated to be soshort and, thus, extremely space-saving due to the arrangement of theindividual accommodating bores in a block as mentioned hereinabove thatthe non-return valve (pump suction valve) which is biased and closes inthe direction of the low pressure accumulator bore 5 may be optimallypositioned therein with least possible structural requirements.

The wheel brake ports HL, HR which likewise lead to the pressure fluidchannels 2′ are arranged on the top side of the accommodating member 1in parallel to the motor accommodating bore 4, which is favorable withrespect to the assembly. This arrangement permits several pipe lines tobe screwed in an unproblematic and easily accessible manner beside amotor housing to be flanged to the motor accommodating bore 4.

Another through-bore 8 is disposed in the accommodating member 1 in acentral position between the two valve rows X, Y. This provision permitsleading an electric plug which projects from the motor housing in ashortest way from the top side to the bottom side of the block-shapedaccommodating member 1 with a view to connecting the plug to a valvecontrol device attached to the bottom side of the accommodating member 1for electrical contacting purposes. The valve control deviceadditionally comprises the control electronics for driving the electricmotor integrated in the motor housing.

FIG. 1a illustrates the advantages of the selected arrangement of boresin the block of the accommodating member 1 by means of pressure fluidchannels 2′, 3′, 5′, 5″ which are arranged exclusively vertically to thesurfaces of the member 1. The arrangement of bores in the block isoptimized to such an extent that merely the pressure fluid channels 2′which are provided for the valve rows X, Y are closed by a ball at thelateral surfaces of the accommodating member 1, that means, they must beclosed by appropriate sealing plugs. In contrast thereto, the pressurefluid channels 3′, 5′ are so favorably chosen that the above-mentionedsealing plugs are eliminated. For example, the pressure fluid channel 3′that connects the noise damping chamber 6 to the brake pressuregenerator port THZ extends radially or tangentially as a straightblind-end bore though the brake pressure generator port THZ into thenoise damping chamber 6. Similarly, the pump suction channel 5′ and thenon-return channel 5″ connected to the second valve row Y is providedfor each brake circuit in the hydraulic aggregate in the way of ablind-end bore into the low pressure accumulator bore 5 which latter,after the accommodation of the low pressure accumulator piston and thepiston return spring, is closed by means of the low pressure accumulatorcover.

The result of the direct arrangement of the pump bore 3 between the lowpressure accumulator bores 5 and the second valve row Y is, in addition,especially short pressure fluid paths, that are optimized in terms ofclearance volume, between the normally closed outlet valves of thesecond valve row Y via the low pressure accumulator 5 to the pump bore3, thereby simplifying the evacuation and filling process necessary forthe initial filling of the hydraulic aggregate.

FIG. 1b shows a cross-section taken through the accommodating member 1known from FIG. 1a at the level of pump bore 3 in order to illustratethe extremely short pump suction channel 5′. What can be easily seen arethe extremely short distances of the pump bore 3 with the noise dampingchambers 6 integrated therein compared to the low pressure accumulatorbores 5 and the valve accommodating bores 2 of the second valve row Yarranged on the respective sides of the pump bore 3. To arrange for thenoise damping chambers 6 at the outer ends of the pump bore 3 there isonly need for two bore steps at both ends which manufacture the pumpsuction channels 5′ by means of a periphery milling tool in thedirection of the low pressure accumulator bores 5. Further, a leakagechannel 4′ can be seen in FIG. 1b which is adjacent to the motoraccommodating bore 4 and penetrates the accommodating member 1 in thedirection of the valve control device that is disposed at the bottomside of the hydraulic aggregate, so that the leakage fluid whichpropagates from the pump bore 3 into the motor accommodating bore 4 canbe taken up and stored in the fluid-tight housing of the valve controldevice.

Different from the preceding embodiments according to FIGS. 1a and 1 b,the embodiment of FIG. 2 exhibits an arrangement of bores in a blockwhich maintains the basic design according to the present inventiondescribed hereinabove, but obviates the need for the already mentionedball-type closure or arrangement of a separate channel closing means forthe pressure fluid channels 2′ in the area of the two valve rows X, Y.This is done by forming the pressure fluid channels 2′ of the firstvalve row X in pairs for each brake circuit from the bottom side of theaccommodating member 1, as shown in the drawing, to extend transverselythrough the valve accommodating bore 2 so that they meet each other atan acute angle in the accommodating member 1 and thus constitute therequired pressure fluid connection between respectively one pair ofinlet valves per brake circuit in the first valve row X. The ball-typeclosing arrangement of the pressure fluid channels 2′ of the secondvalve row Y, as disclosed in FIG. 1a, may also be avoided by connectingthe pressure fluid channels 2′ of the second valve row Y in pairs foreach brake circuit to the valve accommodating bores 2 of thecorresponding brake circuit by way of the associated low pressureaccumulator bore 5. For this purpose, two return channels 5″ in each lowpressure accumulator bore 5 extend directly to the valve accommodatingbores 2 of a preferably diagonal split-up brake circuit, the said bores2 being combined in pairs per valve row Y. Consequently, the lateralarrangement of bores as shown in FIG. 1a has changed in the direction ofthe two valve rows X, Y to such an extent that the pressure fluidchannels 2′ of the two valve rows X, Y no longer have to be additionallyclosed from the outside.

In all previous embodiments of the present invention (FIGS. 1a, 1 b, 2),each pressure fluid channel 3′ that connects the brake pressuregenerator port THZ to the noise damping chamber 6 contains a diaphragmmember 9 to improve noise damping which is inserted through the brakepressure generator port THZ into the pressure fluid channel 3′. Thediaphragm member 9 is positioned between the two valve rows X, Y in thepressure fluid channel 3′ that extends transversely with respect to therows in such a manner that the diaphragm member 9 has no throttlingeffect on the upstream branch line of the pressure fluid channel 3′which leads to the inlet valves of the first valve row X.

In contrast thereto, the diaphragm member 9 in FIG. 3 is inserted fromthe opposite direction into an extension of the pressure fluid channel3′ that passes beside the low pressure accumulator bore 5, whichinsertion is necessary due to a modified connection pattern for themouths of the brake pressure generator ports THZ and wheel brake portsVR, VL, HR, HL that open into the associated pressure fluid channels 2′,3′. Due to the arrangement of the brake pressure generator port THZ nowoffset from the longitudinal axis of the channel, the pressure fluidchannel 3′ leads in each case from the lateral surface that contains thelow pressure accumulator bore 5, traversing the pump or noise dampingchamber 3, 6, to the first valve row X. In other respects, thearrangement of bores in the block corresponds in all basic features tothe embodiments of this invention according to FIGS. 1a, 1 b.

What is claimed is:
 1. Hydraulic aggregate for a slip-controlled brakesystem, comprising: an accommodating member which receives inlet andoutlet valves in several valve accommodating bores of a first and secondvalve row, a pump bore arranged outside the two valve rows in theaccommodating member and pointing transversely to the direction thevalve accommodating bores open into the accommodating member, a motoraccommodating bore arranged outside the two valve rows in theaccommodating member and pointing vertically to the pump bore, two lowpressure accumulator bores which open outside the two valve rows intothe accommodating member and open into the accommodating membervertically to the axes of the valve accommodating bores and the pumpbore, two hollow-cylindrical noise damping chambers connected to thepump bore and being in a hydraulic connection to two brake pressuregenerator ports that open into the accommodating member, severalpressure fluid channels that connect the valve accommodating bores, pumpbores, and low pressure accumulator bores and are adapted to provide ahydraulic connection between the brake pressure generator ports thatopen into the accommodating member and the wheel brake ports, whereinthe two noise damping chambers are integrated in the pump bore, andwherein the brake pressure generator ports have a hydraulic connectionto the noise damping chambers by way of pressure fluid channels thatopen radially or tangentially into the pump bore, the said pressurefluid channels being connected to the valve accommodating bores of thefirst valve row that accommodates the inlet valves wherein the wheelbrake ports and/or the brake pressure generator ports are arranged atleast partly in parallel to the motor accommodating bore, and the portsopen into the accommodating member beside a motor housing that projectsfrom the motor accommodating bore at the top side of the accommodatingmember.
 2. Hydraulic aggregate as claimed in claim 1, wherein the twonoise damping chambers are arranged at the diametrally positioned endsof the pump bore, and wherein both the two noise damping chambers andthe pump bore are pressure-fluid tightly closed by means of closuremembers inserted from outwards into the two lateral surfaces of theaccommodating member.
 3. Hydraulic aggregate as claimed in claim 1,wherein there is provision of pump suction channels between the lowpressure accumulator bores and the pump bore, the said channels openingat right angles into pump bore and being made preferably by a millingoperation on the inside periphery of the pump bore.
 4. Hydraulicaggregate as claimed in claim 1, wherein the pump bore has an axialoffset on either side of the motor accommodating bore.
 5. Hydraulicaggregate as claimed in claim 1, wherein the second valve row comprisesexclusively the valve accommodating bores for the outlet valves whichare disposed between the pump bore and the first valve row thatexclusively includes the valve accommodating bores for the inlet valves,with the result that the second valve row extends directly alongside thepump bore.
 6. Hydraulic aggregate as claimed in claim 3, wherein anon-return valve which is biassed and closes in the direction of the lowpressure accumulator bore is installed in the pump suction channel. 7.Hydraulic aggregate as claimed in claim 1, wherein fitted on the bottomside of the accommodating member opposite to the motor housing is avalve control device which additionally comprises the controlelectronics for driving an electric motor for a radial piston pumpintegrated in the motor housing, and an electric plug of the electricmotor projects through a through-bore disposed between the two valverows and makes a contact with the valve control device.